LAKE PLACID, Fla. (AP) — Authorities say 33 children and three adults were hospitalized after falling ill during a summer camp in Florida. Most of them complained of nausea and vomiting and have been released from the hospital.

The University of Florida Institute of Food and Agriculture Sciences said in a statement that the remaining 87 campers who did not fall ill will return home as planned on Friday.

The camp will be thoroughly cleaned before a new group of campers arrives on Monday.

The Highlands County Health Department is searching for the cause of the illness, which is not thought to be serious. The camp is in Lake Placid, which is northwest of Lake Okeechobee in central Florida.